Effect of photobiomodulation therapy as an adjunct to scaling and root planing in a rat model of ligature-induced periodontitis: a histological and radiographic study

This study aimed to histologically and radiographically evaluate the effectiveness of low-intensity laser irradiation of different wavelengths (660 or 808 nm) as an adjunct to scaling and root planing in the treatment of experimental periodontitis in rats. Periodontitis was induced by placing a ligature around the mandibular first molar of the rats. In total, 40 Wistar rats were randomly divided into five groups (n = 8 each): control (CG), periodontal disease (PD), scaling and root planing (SRP), SRP + 660 nm laser (GL660) and SRP + 808 nm laser (GL808). Groups with laser use received radiation at 6 points in the first molar. The animals were euthanized at baseline and at 7 and 14 days after the interventions. Mandibles were surgically removed for histomorphometric and radiographic assessment of periodontal tissues. The GL660 group showed lesser bone loss than the PD group (P < 0.05) and greater alveolar bone margin after 14 days, indicating a better long-term treatment response (P < 0.05). These findings suggest that SRP with the 660 nm laser as an adjunct results in more favorable radiographic and histological responses than the 808 nm laser.